The invention relates to a fluid powered operative instrumentality, which is fitted with an operative unit able to be controlled by an electro-fluidic control unit.
The German patent publication 20,105,448.5 (utility model) discloses a fluid power operative instrumentality constituting a fluid power parallel gripper. Such a parallel gripper possesses two operative elements in the form of fluid power drives, which are able to be actuated by controlled supply of fluid. As a rule operation is controlled by electrically operated control valves on the supply side. The control valves employed are adapted to the control functions to be performed as regards their type.
In the case of the known operative instrumentality the control valves are in the form of separate, external components. However, it would be conceivable to have the valves in the form of an electro-fluidic control unit constituting a direct component of the fluid power operative instrumentality. If in this manner operative instrumentalities with different operative units, that is to say for example different types of gripping tools, are needed, the design becomes highly complex owing to the use of suitably adapted control units. For reasons of space availability and costs it is possible for instance to combine 3/2, 5/2 the and/or 5/3 valve functions in a suitable fashion. Owing to their specific function they are always associated with a certain operative unit or, respectively, a certain set of movements, dependent on whether within the operative unit for example linear drives or rotary drives or indeed a different number of drives is employed. As a consequence of such inflexibility it is possible, in the case of an integrated design, for the control valves to be designed as a specifically adapted, permanent part of the operative instrumentality. This will apply furthermore even when for reasons of space there is a separation in space of the electro-fluidic control unit and the operative unit.
One object of the invention is to create a fluid power operative instrumentality, which possesses a flexible and highly economic design having only a small number of components.
In order to achieve these and/or other objects appearing from the present specification, claims and drawings, in the present invention a fluid power operative instrumentality comprises an electro-fluidic control unit which possesses a first assembly interface, and at least one interchangeable operative unit having at least one fluid power operative element and possessing a second assembly interface provided for releasable mounting on the first assembly interface, the control unit comprising a plurality of electrically activatable control valves each with a 2/2 valve function and which are provided for fluid control of the employed operative unit and are able to be operated by means of electronic control circuitry in a different respective manner adapted to each other in order to be able to operate operative units, which are alternatively coupled with the control unit, having different types of fluid power customization.
This means that there is the possibility of designing a fluid power operative instrumentality maintaining a standardized form of electro-fluidic control unit if necessary with different operative units, which are different as regards their fluid power customization. The control unit and the operative units are admittedly able to be permanently connected together by way of matching assembly interfaces, but however are functionally decoupled from one another. Owing to the electronic control circuitry present and the standardized design of the control unit with a plurality of control valves each having a 2/2 valve function optimized adaptation, as regards the control technique, to the respectively mounted operative unit is possible. There is as it were a separation between an adaptable control valve group and operative units with an application-related customization. Within the control unit adaptable and preferably freely programmable functional arrays may be built up from a maximally compacted multiple arrangement of control valve units having an identical basic function, which may also be pilot controlled, in conjunction with operative units which are different as regards application and which already comprise the function defining linking of fluid ducts (but not however the associated control valves) necessary for their operation.
Although the patent publication WO/58859 A1 does disclose a micro-valve arrangement comprising an electro-fluidic control unit and equipped with electronic control circuitry and a plurality of 2/2 control valves, there is no provision for coupling with a controlled operative unit. Even if one were to consider fitting an operative unit directly with such known micro-valve arrangement, it would be necessary in addition to have a respectively specific, individual linking of the fluid ducts present. Such a measure is however unnecessary in the case of the operative instrumentality in accordance with the invention, in the case of which the fluid duct system defining function and specifically adapted to one operative unit, belongs to the fluid power design of the respective operative unit and is permanently customized so that circuit measures which may be changed as regards fluid ducts are not necessary.
Further advantageous developments of the invention are defined in the claims.
The operative units provided for operation with the control unit may at least partially constitute tools, as for example mechanically or suction operated gripper tools or other tools, which are able to be employed for materials handling.
The electronic control circuitry may in principle be arranged externally of the electro-fluidic control unit, a particularly compact arrangement with short connections is however made possible by a design, in which the electronic control circuitry is designed in the form of a component of the control unit.
It is convenient for there to be a type-specific encoding means on the respective operative unit, such encoding corresponding to the respectively associated type of operative unit and predetermining the manner of operation, necessary for the control valves, i.e. the functional linking of the 2/2 basic functions of the valve.
Encoding of the operative units may also be employed for the correlation of sensor signals, if the operative units are provided with sensor means, which, when the first and second assembly interfaces are placed together, may transmit sensor signals as regards the operational state of the operative unit to the control unit and more especially to the electronic control circuitry.
The electronic control circuitry may be designed to produce different valve functionalities by the grouped linking of control valves. For instance, higher order valve functions could be produced by logical linking of individual 2/2 valve functions or however larger flow cross sections could thus be produced by parallel circuiting or pseudo-proportional valve functions by parallel circuiting and logical linking.
By way of the electronic control circuitry the switching state of the control valves may be adapted to suit the requirements of the respective operative unit in a flexible, specific fashion.
The electronic control circuitry preferably comprises a memory in which the data, relevant for the manners of operation necessary for the different operative units, of the control valves may be stored and retrieved as required. There is more particularly a provision such that the respectively mounted operative unit causes an automatic retrieval of the manner of operation data intended for it.
Further advantageous developments and convenient forms of the invention will be understood from the following detailed descriptive disclosure of embodiments thereof in conjunction with the accompanying drawings.